Cytotoxic T-lymphocyte-associated antigen-4 blockage can induce autoimmune hypophysitis in patients with metastatic melanoma and renal cancer.

Cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) is an immunoregulatory molecule expressed by activated T cells and resting CD4CD25 T cells. In patients with advanced melanoma, our group reported that administration of anti-CTLA-4 antibody mediated objective cancer regression in 13% of patients. This study also established that the blockade of CTLA-4 was associated with grade III/IV autoimmune manifestations that included dermatitis, enterocolitis, hepatitis, uveitis, and a single case of hypophysitis. Since this initial report, 7 additional patients with anti-CTLA-4 antibody-induced autoimmune hypophysitis have been accumulated. The characteristics, clinical course, laboratory values, radiographic findings, and treatment of these 8 patients are the focus of this report.